If I understand correctly, you don't want a user to have multiple sessions. I'm not sure of which version it started but it should work perfectly from Pega 7.2 for single nodes and from Pega 7.3 on multiple nodes.

Please follow the below steps for stopping concurrent sessions:

• Go to instances of record type system(records explorer>sysadmin>System).
• Open any existing system name and save as that into any name you desire.(let it be abc)
• Open clipboard for that newly created rule and go to page pySaveAsResults of class Data-Admin-System.
• Now change the pyConcurrentSessions value to none from unlimited.
• Save the clipboard and save the rule form.
• Now we have to create "requestor types" for this newly created system name.
• We have to create 4 requestor types namely App, Batch, Portal, Browser.
• For this we can save as the existing requestor types to point to new system name.

After creating all the requestor types we need to change the prconfig.xml to point to new system name. This you can do by the following statement: <env name="Identification/SystemName" value="abc"/> (A restart is required as this is a change in prconfig)

You have to do this in all the nodes.

NOTE: Please check if the requestor types are created properly. Without the requestor types properly created you cannot access the system. You can see all the requestor types from the System->General Landing page(Designer studio>System>general>Systems, nodes and requestors).

--Ravi.